Among gene manipulation techniques using molds as host microorganisms, as a transformation method using Acremonium chrysogenum as a host microorganism, there has been reported a method for transforming protoplasts with a recombinant DNA cloning vector plasmid having a hygromycin B resistant gene (hygromycin B phosphotransferase gene) as a selective marker [see S. W. Queener et al., Microbiology--1985; American Society for Microbiology, p 468 (1985)]. Further, for the purpose of the more efficient expression of a foreign gene in microbial cells of Acremonium chrysogenum, the present applicant has been already filed a patent application directed to an expression vector which utilizes a region containing a promoter and a translation initiation site of .beta.-isopropyl malate dehydrogenase gene cloned from chromosomal DNA of Acremonium chrysogenum (Japanese Patent Laid Open Publication No. 80295/1989).
However, for the potent expression of a foreign gene in microbial cells of Acremonium chrysogenum, there is a difficulty in the former method due to the use of a promoter and a translation initiation site derived from a yeast. Although the latter method utilizes a promoter and a translation initiation site derived from Acremonium chrysogenum, it is yet insufficient for the potent expression of a foreign gene.
The present inventors have cloned DNA containing a gene coding for GLD which is the enzyme involved in glycolytic pathway from chromosomal DNA of Acremonium chrysogenum and have analyzed its gene structure. As a result, it has been found that a region containing the promoter and the translation initiation site of GLD gene can be utilized for the construction of a potent expression vector by using Acremonium chrysogenum as a host microorganism.
The primary structure of GLD gene of Saccharomyces cerevisiae has been already determined [see The Journal of Biological Chemistry, Vol. 254, No. 19, pp 9839-9845 (1979)]and a gene coding for GLD of Aspergilus nidulans has been isolated by using a gene coding for GLD of Saccharomyces cerevisiae as a probe [see Gene, 69, pp 49-57 (1988)]. However, GLD gene of Acremonium chrysogenum and its utilization in a gene manipulation techniques applicable to such a microorganism have not been reported heretofore in the prior art.